When Debbie Toms first started working nights as a respiratory therapist, co-workers teased her that the graveyard shift would "take 10 years off your life," she said. It never occurred to her that there might be some truth to the statement. While Toms has managed to stay healthy in the 30 years that she's worked off and on night shifts, most recently at Kaiser Permanente's Regional Center for Sleep Medicine in San Jose, the graveyard shift has been associated with everything from ulcers and depression to heart disease and cancer. There's even a formal diagnosis called shift work disorder, which applies to people who suffer insomnia and excessive sleepiness from working nights.
See "Keeping the 'grave' out of 'graveyard shift'", Erin Allday, San Francisco Chronicle, March 23, 2008